Merge tag 'v3.16-rc5' into sched/core, to refresh the branch before applying bigger tree-wide changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>

13 files changed, 307 insertions, 124 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index e60837d..33514d8 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -941,6 +941,37 @@ unlock:
 	spin_unlock(ptl);
 }
 
+/*
+ * Save CONFIG_DEBUG_PAGEALLOC from faulting falsely on tail pages
+ * during copy_user_huge_page()'s copy_page_rep(): in the case when
+ * the source page gets split and a tail freed before copy completes.
+ * Called under pmd_lock of checked pmd, so safe from splitting itself.
+ */
+static void get_user_huge_page(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) {
+		struct page *endpage = page + HPAGE_PMD_NR;
+
+		atomic_add(HPAGE_PMD_NR, &page->_count);
+		while (++page < endpage)
+			get_huge_page_tail(page);
+	} else {
+		get_page(page);
+	}
+}
+
+static void put_user_huge_page(struct page *page)
+{
+	if (IS_ENABLED(CONFIG_DEBUG_PAGEALLOC)) {
+		struct page *endpage = page + HPAGE_PMD_NR;
+
+		while (page < endpage)
+			put_page(page++);
+	} else {
+		put_page(page);
+	}
+}
+
 static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
 					struct vm_area_struct *vma,
 					unsigned long address,
@@ -1074,7 +1105,7 @@ int do_huge_pmd_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		ret |= VM_FAULT_WRITE;
 		goto out_unlock;
 	}
-	get_page(page);
+	get_user_huge_page(page);
 	spin_unlock(ptl);
 alloc:
 	if (transparent_hugepage_enabled(vma) &&
@@ -1095,7 +1126,7 @@ alloc:
 				split_huge_page(page);
 				ret |= VM_FAULT_FALLBACK;
 			}
-			put_page(page);
+			put_user_huge_page(page);
 		}
 		count_vm_event(THP_FAULT_FALLBACK);
 		goto out;
@@ -1105,7 +1136,7 @@ alloc:
 		put_page(new_page);
 		if (page) {
 			split_huge_page(page);
-			put_page(page);
+			put_user_huge_page(page);
 		} else
 			split_huge_page_pmd(vma, address, pmd);
 		ret |= VM_FAULT_FALLBACK;
@@ -1127,7 +1158,7 @@ alloc:
 
 	spin_lock(ptl);
 	if (page)
-		put_page(page);
+		put_user_huge_page(page);
 	if (unlikely(!pmd_same(*pmd, orig_pmd))) {
 		spin_unlock(ptl);
 		mem_cgroup_uncharge_page(new_page);
@@ -2392,8 +2423,6 @@ static void collapse_huge_page(struct mm_struct *mm,
 	pmd = mm_find_pmd(mm, address);
 	if (!pmd)
 		goto out;
-	if (pmd_trans_huge(*pmd))
-		goto out;
 
 	anon_vma_lock_write(vma->anon_vma);
 
@@ -2492,8 +2521,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm,
 	pmd = mm_find_pmd(mm, address);
 	if (!pmd)
 		goto out;
-	if (pmd_trans_huge(*pmd))
-		goto out;
 
 	memset(khugepaged_node_load, 0, sizeof(khugepaged_node_load));
 	pte = pte_offset_map_lock(mm, pmd, address, &ptl);
@@ -2846,12 +2873,22 @@ void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
 static void split_huge_page_address(struct mm_struct *mm,
 				    unsigned long address)
 {
+	pgd_t *pgd;
+	pud_t *pud;
 	pmd_t *pmd;
 
 	VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
 
-	pmd = mm_find_pmd(mm, address);
-	if (!pmd)
+	pgd = pgd_offset(mm, address);
+	if (!pgd_present(*pgd))
+		return;
+
+	pud = pud_offset(pgd, address);
+	if (!pud_present(*pud))
+		return;
+
+	pmd = pmd_offset(pud, address);
+	if (!pmd_present(*pmd))
 		return;
 	/*
 	 * Caller holds the mmap_sem write mode, so a huge pmd cannot
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 226910c..2024bbd 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2520,6 +2520,31 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma,
 		update_mmu_cache(vma, address, ptep);
 }
 
+static int is_hugetlb_entry_migration(pte_t pte)
+{
+	swp_entry_t swp;
+
+	if (huge_pte_none(pte) || pte_present(pte))
+		return 0;
+	swp = pte_to_swp_entry(pte);
+	if (non_swap_entry(swp) && is_migration_entry(swp))
+		return 1;
+	else
+		return 0;
+}
+
+static int is_hugetlb_entry_hwpoisoned(pte_t pte)
+{
+	swp_entry_t swp;
+
+	if (huge_pte_none(pte) || pte_present(pte))
+		return 0;
+	swp = pte_to_swp_entry(pte);
+	if (non_swap_entry(swp) && is_hwpoison_entry(swp))
+		return 1;
+	else
+		return 0;
+}
 
 int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 			    struct vm_area_struct *vma)
@@ -2559,10 +2584,26 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 		dst_ptl = huge_pte_lock(h, dst, dst_pte);
 		src_ptl = huge_pte_lockptr(h, src, src_pte);
 		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
-		if (!huge_pte_none(huge_ptep_get(src_pte))) {
+		entry = huge_ptep_get(src_pte);
+		if (huge_pte_none(entry)) { /* skip none entry */
+			;
+		} else if (unlikely(is_hugetlb_entry_migration(entry) ||
+				    is_hugetlb_entry_hwpoisoned(entry))) {
+			swp_entry_t swp_entry = pte_to_swp_entry(entry);
+
+			if (is_write_migration_entry(swp_entry) && cow) {
+				/*
+				 * COW mappings require pages in both
+				 * parent and child to be set to read.
+				 */
+				make_migration_entry_read(&swp_entry);
+				entry = swp_entry_to_pte(swp_entry);
+				set_huge_pte_at(src, addr, src_pte, entry);
+			}
+			set_huge_pte_at(dst, addr, dst_pte, entry);
+		} else {
 			if (cow)
 				huge_ptep_set_wrprotect(src, addr, src_pte);
-			entry = huge_ptep_get(src_pte);
 			ptepage = pte_page(entry);
 			get_page(ptepage);
 			page_dup_rmap(ptepage);
@@ -2578,32 +2619,6 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	return ret;
 }
 
-static int is_hugetlb_entry_migration(pte_t pte)
-{
-	swp_entry_t swp;
-
-	if (huge_pte_none(pte) || pte_present(pte))
-		return 0;
-	swp = pte_to_swp_entry(pte);
-	if (non_swap_entry(swp) && is_migration_entry(swp))
-		return 1;
-	else
-		return 0;
-}
-
-static int is_hugetlb_entry_hwpoisoned(pte_t pte)
-{
-	swp_entry_t swp;
-
-	if (huge_pte_none(pte) || pte_present(pte))
-		return 0;
-	swp = pte_to_swp_entry(pte);
-	if (non_swap_entry(swp) && is_hwpoison_entry(swp))
-		return 1;
-	else
-		return 0;
-}
-
 void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			    unsigned long start, unsigned long end,
 			    struct page *ref_page)
diff --git a/mm/ksm.c b/mm/ksm.c
index 68710e8..346ddc9 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -945,7 +945,6 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
 	pmd = mm_find_pmd(mm, addr);
 	if (!pmd)
 		goto out;
-	BUG_ON(pmd_trans_huge(*pmd));
 
 	mmun_start = addr;
 	mmun_end   = addr + PAGE_SIZE;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index cd8989c..c6399e3 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -895,7 +895,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
 	struct page *hpage = *hpagep;
 	struct page *ppage;
 
-	if (PageReserved(p) || PageSlab(p))
+	if (PageReserved(p) || PageSlab(p) || !PageLRU(p))
 		return SWAP_SUCCESS;
 
 	/*
@@ -1159,9 +1159,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 					action_result(pfn, "free buddy, 2nd try", DELAYED);
 				return 0;
 			}
-			action_result(pfn, "non LRU", IGNORED);
-			put_page(p);
-			return -EBUSY;
 		}
 	}
 
@@ -1194,6 +1191,9 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 		return 0;
 	}
 
+	if (!PageHuge(p) && !PageTransTail(p) && !PageLRU(p))
+		goto identify_page_state;
+
 	/*
 	 * For error on the tail page, we should set PG_hwpoison
 	 * on the head page to show that the hugepage is hwpoisoned
@@ -1243,6 +1243,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
 		goto out;
 	}
 
+identify_page_state:
 	res = -EBUSY;
 	/*
 	 * The first check uses the current page flags which may not have any
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 2849742..8f5330d 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -656,19 +656,18 @@ static unsigned long change_prot_numa(struct vm_area_struct *vma,
  * @nodes and @flags,) it's isolated and queued to the pagelist which is
  * passed via @private.)
  */
-static struct vm_area_struct *
+static int
 queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 		const nodemask_t *nodes, unsigned long flags, void *private)
 {
-	int err;
-	struct vm_area_struct *first, *vma, *prev;
-
+	int err = 0;
+	struct vm_area_struct *vma, *prev;
 
-	first = find_vma(mm, start);
-	if (!first)
-		return ERR_PTR(-EFAULT);
+	vma = find_vma(mm, start);
+	if (!vma)
+		return -EFAULT;
 	prev = NULL;
-	for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
+	for (; vma && vma->vm_start < end; vma = vma->vm_next) {
 		unsigned long endvma = vma->vm_end;
 
 		if (endvma > end)
@@ -678,9 +677,9 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 
 		if (!(flags & MPOL_MF_DISCONTIG_OK)) {
 			if (!vma->vm_next && vma->vm_end < end)
-				return ERR_PTR(-EFAULT);
+				return -EFAULT;
 			if (prev && prev->vm_end < vma->vm_start)
-				return ERR_PTR(-EFAULT);
+				return -EFAULT;
 		}
 
 		if (flags & MPOL_MF_LAZY) {
@@ -694,15 +693,13 @@ queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 
 			err = queue_pages_pgd_range(vma, start, endvma, nodes,
 						flags, private);
-			if (err) {
-				first = ERR_PTR(err);
+			if (err)
 				break;
-			}
 		}
 next:
 		prev = vma;
 	}
-	return first;
+	return err;
 }
 
 /*
@@ -1156,16 +1153,17 @@ out:
 
 /*
  * Allocate a new page for page migration based on vma policy.
- * Start assuming that page is mapped by vma pointed to by @private.
+ * Start by assuming the page is mapped by the same vma as contains @start.
  * Search forward from there, if not.  N.B., this assumes that the
  * list of pages handed to migrate_pages()--which is how we get here--
  * is in virtual address order.
  */
-static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
+static struct page *new_page(struct page *page, unsigned long start, int **x)
 {
-	struct vm_area_struct *vma = (struct vm_area_struct *)private;
+	struct vm_area_struct *vma;
 	unsigned long uninitialized_var(address);
 
+	vma = find_vma(current->mm, start);
 	while (vma) {
 		address = page_address_in_vma(page, vma);
 		if (address != -EFAULT)
@@ -1195,7 +1193,7 @@ int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
 	return -ENOSYS;
 }
 
-static struct page *new_vma_page(struct page *page, unsigned long private, int **x)
+static struct page *new_page(struct page *page, unsigned long start, int **x)
 {
 	return NULL;
 }
@@ -1205,7 +1203,6 @@ static long do_mbind(unsigned long start, unsigned long len,
 		     unsigned short mode, unsigned short mode_flags,
 		     nodemask_t *nmask, unsigned long flags)
 {
-	struct vm_area_struct *vma;
 	struct mm_struct *mm = current->mm;
 	struct mempolicy *new;
 	unsigned long end;
@@ -1271,11 +1268,9 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (err)
 		goto mpol_out;
 
-	vma = queue_pages_range(mm, start, end, nmask,
+	err = queue_pages_range(mm, start, end, nmask,
 			  flags | MPOL_MF_INVERT, &pagelist);
-
-	err = PTR_ERR(vma);	/* maybe ... */
-	if (!IS_ERR(vma))
+	if (!err)
 		err = mbind_range(mm, start, end, new);
 
 	if (!err) {
@@ -1283,9 +1278,8 @@ static long do_mbind(unsigned long start, unsigned long len,
 
 		if (!list_empty(&pagelist)) {
 			WARN_ON_ONCE(flags & MPOL_MF_LAZY);
-			nr_failed = migrate_pages(&pagelist, new_vma_page,
-					NULL, (unsigned long)vma,
-					MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
+			nr_failed = migrate_pages(&pagelist, new_page, NULL,
+				start, MIGRATE_SYNC, MR_MEMPOLICY_MBIND);
 			if (nr_failed)
 				putback_movable_pages(&pagelist);
 		}
@@ -2145,7 +2139,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old)
 	} else
 		*new = *old;
 
-	rcu_read_lock();
 	if (current_cpuset_is_being_rebound()) {
 		nodemask_t mems = cpuset_mems_allowed(current);
 		if (new->flags & MPOL_F_REBINDING)
@@ -2153,7 +2146,6 @@ struct mempolicy *__mpol_dup(struct mempolicy *old)
 		else
 			mpol_rebind_policy(new, &mems, MPOL_REBIND_ONCE);
 	}
-	rcu_read_unlock();
 	atomic_set(&new->refcnt, 1);
 	return new;
 }
diff --git a/mm/migrate.c b/mm/migrate.c
index 63f0cd5..9e0beaa 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -120,8 +120,6 @@ static int remove_migration_pte(struct page *new, struct vm_area_struct *vma,
 		pmd = mm_find_pmd(mm, addr);
 		if (!pmd)
 			goto out;
-		if (pmd_trans_huge(*pmd))
-			goto out;
 
 		ptep = pte_offset_map(pmd, addr);
 
diff --git a/mm/msync.c b/mm/msync.c
index a5c6736..992a167 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -78,7 +78,8 @@ SYSCALL_DEFINE3(msync, unsigned long, start, size_t, len, int, flags)
 			goto out_unlock;
 		}
 		file = vma->vm_file;
-		fstart = start + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
+		fstart = (start - vma->vm_start) +
+			 ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
 		fend = fstart + (min(end, vma->vm_end) - start) - 1;
 		start = vma->vm_end;
 		if ((flags & MS_SYNC) && file &&
diff --git a/mm/nommu.c b/mm/nommu.c
index b78e3a8..4a852f6 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -786,7 +786,7 @@ static void delete_vma_from_mm(struct vm_area_struct *vma)
 	for (i = 0; i < VMACACHE_SIZE; i++) {
 		/* if the vma is cached, invalidate the entire cache */
 		if (curr->vmacache[i] == vma) {
-			vmacache_invalidate(curr->mm);
+			vmacache_invalidate(mm);
 			break;
 		}
 	}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 4f59fa2..0ea758b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -69,6 +69,7 @@
 
 /* prevent >1 _updater_ of zone percpu pageset ->high and ->batch fields */
 static DEFINE_MUTEX(pcp_batch_high_lock);
+#define MIN_PERCPU_PAGELIST_FRACTION	(8)
 
 #ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
 DEFINE_PER_CPU(int, numa_node);
@@ -815,9 +816,21 @@ void __init init_cma_reserved_pageblock(struct page *page)
 		set_page_count(p, 0);
 	} while (++p, --i);
 
-	set_page_refcounted(page);
 	set_pageblock_migratetype(page, MIGRATE_CMA);
-	__free_pages(page, pageblock_order);
+
+	if (pageblock_order >= MAX_ORDER) {
+		i = pageblock_nr_pages;
+		p = page;
+		do {
+			set_page_refcounted(p);
+			__free_pages(p, MAX_ORDER - 1);
+			p += MAX_ORDER_NR_PAGES;
+		} while (i -= MAX_ORDER_NR_PAGES);
+	} else {
+		set_page_refcounted(page);
+		__free_pages(page, pageblock_order);
+	}
+
 	adjust_managed_page_count(page, pageblock_nr_pages);
 }
 #endif
@@ -4145,7 +4158,7 @@ static void __meminit zone_init_free_lists(struct zone *zone)
 	memmap_init_zone((size), (nid), (zone), (start_pfn), MEMMAP_EARLY)
 #endif
 
-static int __meminit zone_batchsize(struct zone *zone)
+static int zone_batchsize(struct zone *zone)
 {
 #ifdef CONFIG_MMU
 	int batch;
@@ -4261,8 +4274,8 @@ static void pageset_set_high(struct per_cpu_pageset *p,
 	pageset_update(&p->pcp, high, batch);
 }
 
-static void __meminit pageset_set_high_and_batch(struct zone *zone,
-		struct per_cpu_pageset *pcp)
+static void pageset_set_high_and_batch(struct zone *zone,
+				       struct per_cpu_pageset *pcp)
 {
 	if (percpu_pagelist_fraction)
 		pageset_set_high(pcp,
@@ -5881,23 +5894,38 @@ int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *table, int write,
 	void __user *buffer, size_t *length, loff_t *ppos)
 {
 	struct zone *zone;
-	unsigned int cpu;
+	int old_percpu_pagelist_fraction;
 	int ret;
 
+	mutex_lock(&pcp_batch_high_lock);
+	old_percpu_pagelist_fraction = percpu_pagelist_fraction;
+
 	ret = proc_dointvec_minmax(table, write, buffer, length, ppos);
-	if (!write || (ret < 0))
-		return ret;
+	if (!write || ret < 0)
+		goto out;
+
+	/* Sanity checking to avoid pcp imbalance */
+	if (percpu_pagelist_fraction &&
+	    percpu_pagelist_fraction < MIN_PERCPU_PAGELIST_FRACTION) {
+		percpu_pagelist_fraction = old_percpu_pagelist_fraction;
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* No change? */
+	if (percpu_pagelist_fraction == old_percpu_pagelist_fraction)
+		goto out;
 
-	mutex_lock(&pcp_batch_high_lock);
 	for_each_populated_zone(zone) {
-		unsigned long  high;
-		high = zone->managed_pages / percpu_pagelist_fraction;
+		unsigned int cpu;
+
 		for_each_possible_cpu(cpu)
-			pageset_set_high(per_cpu_ptr(zone->pageset, cpu),
-					 high);
+			pageset_set_high_and_batch(zone,
+					per_cpu_ptr(zone->pageset, cpu));
 	}
+out:
 	mutex_unlock(&pcp_batch_high_lock);
-	return 0;
+	return ret;
 }
 
 int hashdist = HASHDIST_DEFAULT;
diff --git a/mm/rmap.c b/mm/rmap.c
index bf05fc8..b7e94eb 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -569,6 +569,7 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
 	pgd_t *pgd;
 	pud_t *pud;
 	pmd_t *pmd = NULL;
+	pmd_t pmde;
 
 	pgd = pgd_offset(mm, address);
 	if (!pgd_present(*pgd))
@@ -579,7 +580,13 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
 		goto out;
 
 	pmd = pmd_offset(pud, address);
-	if (!pmd_present(*pmd))
+	/*
+	 * Some THP functions use the sequence pmdp_clear_flush(), set_pmd_at()
+	 * without holding anon_vma lock for write.  So when looking for a
+	 * genuine pmde (in which to find pte), test present and !THP together.
+	 */
+	pmde = ACCESS_ONCE(*pmd);
+	if (!pmd_present(pmde) || pmd_trans_huge(pmde))
 		pmd = NULL;
 out:
 	return pmd;
@@ -615,9 +622,6 @@ pte_t *__page_check_address(struct page *page, struct mm_struct *mm,
 	if (!pmd)
 		return NULL;
 
-	if (pmd_trans_huge(*pmd))
-		return NULL;
-
 	pte = pte_offset_map(pmd, address);
 	/* Make a quick check before getting the lock */
 	if (!sync && !pte_present(*pte)) {
diff --git a/mm/shmem.c b/mm/shmem.c
index f484c27..1140f49 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -80,11 +80,12 @@ static struct vfsmount *shm_mnt;
 #define SHORT_SYMLINK_LEN 128
 
 /*
- * shmem_fallocate and shmem_writepage communicate via inode->i_private
- * (with i_mutex making sure that it has only one user at a time):
- * we would prefer not to enlarge the shmem inode just for that.
+ * shmem_fallocate communicates with shmem_fault or shmem_writepage via
+ * inode->i_private (with i_mutex making sure that it has only one user at
+ * a time): we would prefer not to enlarge the shmem inode just for that.
  */
 struct shmem_falloc {
+	int	mode;		/* FALLOC_FL mode currently operating */
 	pgoff_t start;		/* start of range currently being fallocated */
 	pgoff_t next;		/* the next page offset to be fallocated */
 	pgoff_t nr_falloced;	/* how many new pages have been fallocated */
@@ -759,6 +760,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
 			spin_lock(&inode->i_lock);
 			shmem_falloc = inode->i_private;
 			if (shmem_falloc &&
+			    !shmem_falloc->mode &&
 			    index >= shmem_falloc->start &&
 			    index < shmem_falloc->next)
 				shmem_falloc->nr_unswapped++;
@@ -1027,6 +1029,9 @@ repeat:
 		goto failed;
 	}
 
+	if (page && sgp == SGP_WRITE)
+		mark_page_accessed(page);
+
 	/* fallocated page? */
 	if (page && !PageUptodate(page)) {
 		if (sgp != SGP_READ)
@@ -1108,6 +1113,9 @@ repeat:
 		shmem_recalc_inode(inode);
 		spin_unlock(&info->lock);
 
+		if (sgp == SGP_WRITE)
+			mark_page_accessed(page);
+
 		delete_from_swap_cache(page);
 		set_page_dirty(page);
 		swap_free(swap);
@@ -1134,6 +1142,9 @@ repeat:
 
 		__SetPageSwapBacked(page);
 		__set_page_locked(page);
+		if (sgp == SGP_WRITE)
+			init_page_accessed(page);
+
 		error = mem_cgroup_charge_file(page, current->mm,
 						gfp & GFP_RECLAIM_MASK);
 		if (error)
@@ -1233,6 +1244,44 @@ static int shmem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	int error;
 	int ret = VM_FAULT_LOCKED;
 
+	/*
+	 * Trinity finds that probing a hole which tmpfs is punching can
+	 * prevent the hole-punch from ever completing: which in turn
+	 * locks writers out with its hold on i_mutex.  So refrain from
+	 * faulting pages into the hole while it's being punched, and
+	 * wait on i_mutex to be released if vmf->flags permits.
+	 */
+	if (unlikely(inode->i_private)) {
+		struct shmem_falloc *shmem_falloc;
+
+		spin_lock(&inode->i_lock);
+		shmem_falloc = inode->i_private;
+		if (!shmem_falloc ||
+		    shmem_falloc->mode != FALLOC_FL_PUNCH_HOLE ||
+		    vmf->pgoff < shmem_falloc->start ||
+		    vmf->pgoff >= shmem_falloc->next)
+			shmem_falloc = NULL;
+		spin_unlock(&inode->i_lock);
+		/*
+		 * i_lock has protected us from taking shmem_falloc seriously
+		 * once return from shmem_fallocate() went back up that stack.
+		 * i_lock does not serialize with i_mutex at all, but it does
+		 * not matter if sometimes we wait unnecessarily, or sometimes
+		 * miss out on waiting: we just need to make those cases rare.
+		 */
+		if (shmem_falloc) {
+			if ((vmf->flags & FAULT_FLAG_ALLOW_RETRY) &&
+			   !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) {
+				up_read(&vma->vm_mm->mmap_sem);
+				mutex_lock(&inode->i_mutex);
+				mutex_unlock(&inode->i_mutex);
+				return VM_FAULT_RETRY;
+			}
+			/* cond_resched? Leave that to GUP or return to user */
+			return VM_FAULT_NOPAGE;
+		}
+	}
+
 	error = shmem_getpage(inode, vmf->pgoff, &vmf->page, SGP_CACHE, &ret);
 	if (error)
 		return ((error == -ENOMEM) ? VM_FAULT_OOM : VM_FAULT_SIGBUS);
@@ -1372,13 +1421,9 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
 			loff_t pos, unsigned len, unsigned flags,
 			struct page **pagep, void **fsdata)
 {
-	int ret;
 	struct inode *inode = mapping->host;
 	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
-	ret = shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
-	if (ret == 0 && *pagep)
-		init_page_accessed(*pagep);
-	return ret;
+	return shmem_getpage(inode, index, pagep, SGP_WRITE, NULL);
 }
 
 static int
@@ -1724,20 +1769,31 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 	pgoff_t start, index, end;
 	int error;
 
+	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+		return -EOPNOTSUPP;
+
 	mutex_lock(&inode->i_mutex);
 
+	shmem_falloc.mode = mode & ~FALLOC_FL_KEEP_SIZE;
+
 	if (mode & FALLOC_FL_PUNCH_HOLE) {
 		struct address_space *mapping = file->f_mapping;
 		loff_t unmap_start = round_up(offset, PAGE_SIZE);
 		loff_t unmap_end = round_down(offset + len, PAGE_SIZE) - 1;
 
+		shmem_falloc.start = unmap_start >> PAGE_SHIFT;
+		shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT;
+		spin_lock(&inode->i_lock);
+		inode->i_private = &shmem_falloc;
+		spin_unlock(&inode->i_lock);
+
 		if ((u64)unmap_end > (u64)unmap_start)
 			unmap_mapping_range(mapping, unmap_start,
 					    1 + unmap_end - unmap_start, 0);
 		shmem_truncate_range(inode, offset, offset + len - 1);
 		/* No need to unmap again: hole-punching leaves COWed pages */
 		error = 0;
-		goto out;
+		goto undone;
 	}
 
 	/* We need to check rlimit even when FALLOC_FL_KEEP_SIZE */
diff --git a/mm/slab.c b/mm/slab.c
index 9ca3b87..3070b92 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -386,6 +386,39 @@ static void **dbg_userword(struct kmem_cache *cachep, void *objp)
 
 #endif
 
+#define OBJECT_FREE (0)
+#define OBJECT_ACTIVE (1)
+
+#ifdef CONFIG_DEBUG_SLAB_LEAK
+
+static void set_obj_status(struct page *page, int idx, int val)
+{
+	int freelist_size;
+	char *status;
+	struct kmem_cache *cachep = page->slab_cache;
+
+	freelist_size = cachep->num * sizeof(freelist_idx_t);
+	status = (char *)page->freelist + freelist_size;
+	status[idx] = val;
+}
+
+static inline unsigned int get_obj_status(struct page *page, int idx)
+{
+	int freelist_size;
+	char *status;
+	struct kmem_cache *cachep = page->slab_cache;
+
+	freelist_size = cachep->num * sizeof(freelist_idx_t);
+	status = (char *)page->freelist + freelist_size;
+
+	return status[idx];
+}
+
+#else
+static inline void set_obj_status(struct page *page, int idx, int val) {}
+
+#endif
+
 /*
  * Do not go above this order unless 0 objects fit into the slab or
  * overridden on the command line.
@@ -576,12 +609,30 @@ static inline struct array_cache *cpu_cache_get(struct kmem_cache *cachep)
 	return cachep->array[smp_processor_id()];
 }
 
+static size_t calculate_freelist_size(int nr_objs, size_t align)
+{
+	size_t freelist_size;
+
+	freelist_size = nr_objs * sizeof(freelist_idx_t);
+	if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+		freelist_size += nr_objs * sizeof(char);
+
+	if (align)
+		freelist_size = ALIGN(freelist_size, align);
+
+	return freelist_size;
+}
+
 static int calculate_nr_objs(size_t slab_size, size_t buffer_size,
 				size_t idx_size, size_t align)
 {
 	int nr_objs;
+	size_t remained_size;
 	size_t freelist_size;
+	int extra_space = 0;
 
+	if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+		extra_space = sizeof(char);
 	/*
 	 * Ignore padding for the initial guess. The padding
 	 * is at most @align-1 bytes, and @buffer_size is at
@@ -590,14 +641,15 @@ static int calculate_nr_objs(size_t slab_size, size_t buffer_size,
 	 * into the memory allocation when taking the padding
 	 * into account.
 	 */
-	nr_objs = slab_size / (buffer_size + idx_size);
+	nr_objs = slab_size / (buffer_size + idx_size + extra_space);
 
 	/*
 	 * This calculated number will be either the right
 	 * amount, or one greater than what we want.
 	 */
-	freelist_size = slab_size - nr_objs * buffer_size;
-	if (freelist_size < ALIGN(nr_objs * idx_size, align))
+	remained_size = slab_size - nr_objs * buffer_size;
+	freelist_size = calculate_freelist_size(nr_objs, align);
+	if (remained_size < freelist_size)
 		nr_objs--;
 
 	return nr_objs;
@@ -635,7 +687,7 @@ static void cache_estimate(unsigned long gfporder, size_t buffer_size,
 	} else {
 		nr_objs = calculate_nr_objs(slab_size, buffer_size,
 					sizeof(freelist_idx_t), align);
-		mgmt_size = ALIGN(nr_objs * sizeof(freelist_idx_t), align);
+		mgmt_size = calculate_freelist_size(nr_objs, align);
 	}
 	*num = nr_objs;
 	*left_over = slab_size - nr_objs*buffer_size - mgmt_size;
@@ -2041,13 +2093,16 @@ static size_t calculate_slab_order(struct kmem_cache *cachep,
 			break;
 
 		if (flags & CFLGS_OFF_SLAB) {
+			size_t freelist_size_per_obj = sizeof(freelist_idx_t);
 			/*
 			 * Max number of objs-per-slab for caches which
 			 * use off-slab slabs. Needed to avoid a possible
 			 * looping condition in cache_grow().
 			 */
+			if (IS_ENABLED(CONFIG_DEBUG_SLAB_LEAK))
+				freelist_size_per_obj += sizeof(char);
 			offslab_limit = size;
-			offslab_limit /= sizeof(freelist_idx_t);
+			offslab_limit /= freelist_size_per_obj;
 
  			if (num > offslab_limit)
 				break;
@@ -2294,8 +2349,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 	if (!cachep->num)
 		return -E2BIG;
 
-	freelist_size =
-		ALIGN(cachep->num * sizeof(freelist_idx_t), cachep->align);
+	freelist_size = calculate_freelist_size(cachep->num, cachep->align);
 
 	/*
 	 * If the slab has been placed off-slab, and we have enough space then
@@ -2308,7 +2362,7 @@ __kmem_cache_create (struct kmem_cache *cachep, unsigned long flags)
 
 	if (flags & CFLGS_OFF_SLAB) {
 		/* really off slab. No need for manual alignment */
-		freelist_size = cachep->num * sizeof(freelist_idx_t);
+		freelist_size = calculate_freelist_size(cachep->num, 0);
 
 #ifdef CONFIG_PAGE_POISONING
 		/* If we're going to use the generic kernel_map_pages()
@@ -2612,6 +2666,7 @@ static void cache_init_objs(struct kmem_cache *cachep,
 		if (cachep->ctor)
 			cachep->ctor(objp);
 #endif
+		set_obj_status(page, i, OBJECT_FREE);
 		set_free_obj(page, i, i);
 	}
 }
@@ -2820,6 +2875,7 @@ static void *cache_free_debugcheck(struct kmem_cache *cachep, void *objp,
 	BUG_ON(objnr >= cachep->num);
 	BUG_ON(objp != index_to_obj(cachep, page, objnr));
 
+	set_obj_status(page, objnr, OBJECT_FREE);
 	if (cachep->flags & SLAB_POISON) {
 #ifdef CONFIG_DEBUG_PAGEALLOC
 		if ((cachep->size % PAGE_SIZE)==0 && OFF_SLAB(cachep)) {
@@ -2953,6 +3009,8 @@ static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep,
 static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
 				gfp_t flags, void *objp, unsigned long caller)
 {
+	struct page *page;
+
 	if (!objp)
 		return objp;
 	if (cachep->flags & SLAB_POISON) {
@@ -2983,6 +3041,9 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep,
 		*dbg_redzone1(cachep, objp) = RED_ACTIVE;
 		*dbg_redzone2(cachep, objp) = RED_ACTIVE;
 	}
+
+	page = virt_to_head_page(objp);
+	set_obj_status(page, obj_to_index(cachep, page, objp), OBJECT_ACTIVE);
 	objp += obj_offset(cachep);
 	if (cachep->ctor && cachep->flags & SLAB_POISON)
 		cachep->ctor(objp);
@@ -4219,21 +4280,12 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c,
 						struct page *page)
 {
 	void *p;
-	int i, j;
+	int i;
 
 	if (n[0] == n[1])
 		return;
 	for (i = 0, p = page->s_mem; i < c->num; i++, p += c->size) {
-		bool active = true;
-
-		for (j = page->active; j < c->num; j++) {
-			/* Skip freed item */
-			if (get_free_obj(page, j) == i) {
-				active = false;
-				break;
-			}
-		}
-		if (!active)
+		if (get_obj_status(page, i) != OBJECT_ACTIVE)
 			continue;
 
 		if (!add_caller(n, (unsigned long)*dbg_userword(c, p)))
diff --git a/mm/slub.c b/mm/slub.c
index b2b0473..7300480 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1881,7 +1881,7 @@ redo:
 
 	new.frozen = 0;
 
-	if (!new.inuse && n->nr_partial > s->min_partial)
+	if (!new.inuse && n->nr_partial >= s->min_partial)
 		m = M_FREE;
 	else if (new.freelist) {
 		m = M_PARTIAL;
@@ -1992,7 +1992,7 @@ static void unfreeze_partials(struct kmem_cache *s,
 				new.freelist, new.counters,
 				"unfreezing slab"));
 
-		if (unlikely(!new.inuse && n->nr_partial > s->min_partial)) {
+		if (unlikely(!new.inuse && n->nr_partial >= s->min_partial)) {
 			page->next = discard_page;
 			discard_page = page;
 		} else {
@@ -2620,7 +2620,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
                 return;
         }
 
-	if (unlikely(!new.inuse && n->nr_partial > s->min_partial))
+	if (unlikely(!new.inuse && n->nr_partial >= s->min_partial))
 		goto slab_empty;
 
 	/*